The Whiteboard applet is a Java based applet (compatible to Java 1.1, so it should run even in older browsers) which allows visitors of a website to work together at drawing images, sketches, charts etc. All actions someone takes will be synchronized to the other users.
This is especially useful if there is another, speech based, connection between the participants, like voice-over-ip, teamspeak or similar solutions.
Its main goal is to remain platform independent and work for everyone - so there is no need to open incoming ports for using it.
There are 2 different modes: either using a special server for it (on the same host that serves the web site) or a polling HTTP protocol - the former creates less traffic, the latter works for more site hosters (since usually you may not open your own ports on webhoster's servers).
As backend to cache objects, a MySQL database is used (for the PHTTP mode, the server mode caches everything in RAM), but it should be quite straightforward to change this (the whole backend is about 200 lines of PHP code).
The applet is tested on Mozilla, Opera, Netscape 4.x, Internet Explorer on Windows, and Mozilla on Linux and Mozilla on Mac. It should work on others as well.
A list of frequently asked questions (FAQs).
Some internals of the implementation.
I know, this is not much documentation. If you have questions (or want to contribute better documentation) drop me an e-mail.
Singleuser demo (no synchronization).
The Whiteboard applet requires a Java Plugin for your browser (At least version 1.1) You can download a free one from Sun from www.java.com.
Binary download (Version 1.0, 79 KB)
Source download (Version 1.0, 18 KB)
You can also get the latest "bleeding edge" source code from CVS.
Browse it or use the following commands to check it out anonymously:
cvs -z3 -d:pserver:firstname.lastname@example.org:/cvsroot/wbapplet co wbapplet